Matrix: HB/494_bus
Description: S ADMITTANCE MATRIX 494 BUS POWER SYSTEM, D.J.TYLAVSKY, JULY 1985.
![]() |
| (undirected graph drawing) |
![]() |
| Matrix properties | |
| number of rows | 494 |
| number of columns | 494 |
| nonzeros | 1,666 |
| structural full rank? | yes |
| structural rank | 494 |
| # of blocks from dmperm | 1 |
| # strongly connected comp. | 1 |
| explicit zero entries | 0 |
| nonzero pattern symmetry | symmetric |
| numeric value symmetry | symmetric |
| type | real |
| structure | symmetric |
| Cholesky candidate? | yes |
| positive definite? | yes |
| author | D. Tylavsky |
| editor | I. Duff, R. Grimes, J. Lewis |
| date | 1985 |
| kind | power network problem |
| 2D/3D problem? | no |
| Ordering statistics: | result |
| nnz(chol(P*(A+A'+s*I)*P')) with AMD | 1,414 |
| Cholesky flop count | 4.8e+03 |
| nnz(L+U), no partial pivoting, with AMD | 2,334 |
| nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 1,776 |
| nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 3,446 |
| SVD-based statistics: | |
| norm(A) | 30005.1 |
| min(svd(A)) | 0.0124224 |
| cond(A) | 2.41541e+06 |
| rank(A) | 494 |
| sprank(A)-rank(A) | 0 |
| null space dimension | 0 |
| full numerical rank? | yes |
| singular values (MAT file): | click here |
| SVD method used: | s = svd (full (A)) ; |
| status: | ok |

For a description of the statistics displayed above, click here.
Maintained by Tim Davis, last updated 12-Mar-2014.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.